[技术]Arizona眼睛模型 [复制链接]

简介 c]B$i*t  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 sE{pzPq!  
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模型 fSDi-I  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 8.bKb<y  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. dz>;<&2Z  
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光源 |w}xl'>q  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 HG'{J^t  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Vx_rc%'  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 9z?oB&5  
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视网膜的散射 2k6 X,  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 2wqk,c[]  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ZtVAEIZ)  
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脚本 P\CDd=yWc  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ^7]"kg DA  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 iA_8(Yo  
余下的脚本计算与屈光度有关的所有参数。 N?dvuB  
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分析 a:YI"*S  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 mYB`)M*Y  
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脚本代码 +&
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. t<:D@J]a  
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Dim entity As T_ENTITY nRhrWS  
Dim op As T_OPERATION +kdyS
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Dim mat As T_MODELMATERIAL wxLXh6|6%_  
Dim A As Double 1gO2C$  
Dim pupilDiam As Double IGX:H)&*  
Dim eID As Long "%8A:^1  
Dim parID As Long 0h$GI"dR  
Dim count As Integer h!&sNzX  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double m8+(%>+
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Dim tlens As Double, nlens As Double yj@tV2  
Dim curv As Double, conic As Double T)7TyE|"2g  
Dim ok As Long !/K8xD$  
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Sub Main o?Sla_D   
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    '用户输入对话框 RK9>dk
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0BkV/v1Uc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 N$?cX(|7  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 tqOi x/  
        OKButton 40,91,90,21 j_?cpm{~ml  
        CancelButton 190,91,90,21 ,$r2gr!_G  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Q"a2.9
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        TextBox 220,49,40,21,.TextBox2 'default: 4 sc`"P-J+vp  
    End Dialog A,~Hl
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    Dim dlg As UserDialog  Kn+=lCk  
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    ok = Dialog (dlg)  *2u E  
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    If ok=0 Then    'cancel button was pressed FYPz 4K  
        Print "Execution cancelled." yt.c5>B^  
        End >e5zrgV  
    End If !^U6Z@&/R  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .")b?#K  
    If dlg.TextBox1 = "" Then & %}/AoU  
        A = 0           'Default accommodation <z#BsnjW{  
    Else ]>:^d%n,}  
        A = CDbl(dlg.TextBox1) <D/al9  
    End If ){Z  
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    If dlg.TextBox2 = "" Then snk$^  
        pupilDiam = 4   'Default pupil diameter zjbE 7^N  
    Else 3 %(Y$8U  
        pupilDiam = CDbl(dlg.TextBox2) `]2@_wa  
    End If [J\DB)V/  
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    Print " " 7{BnXN[  
    Print "Accommodation = " & A & " Diopters" H$!-f>Rxa  
    Print "Pupil Diameter = " & pupilDiam & " mm" !Cj(A"uqY  
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    ' Calculate new parameters with accommodation #0MK(Ut/  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness t/:w1rw  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens SR*Gqx  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 4e%8D`/=M  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :zL393(  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 5}<[[}(  
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    tlens = 3.767 + 0.04*A                  'Lens thickness nlfPg-78B+  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }z'DWp=uN  
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    'Adjust parameters to account for accommodation N^$9;CKP=  
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    '************************************************************************* ^tE_LL+ji|  
    'Aqueous thickness (Position of Lens) Y$8; Gm<)  
    '************************************************************************* AUAI3K?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,RK3eQ  
    GetCustomElement eID, entity qc0 B<,x7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) O_CT+Ou  
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    ' Delete any shift(s) in z q:yO92Ow  
    count = 0 3_J>y  
    While GetOperationCount(eID)>count ="lI i$>O  
        GetOperation eID, count, op V<-htV  
        If op.Type="ShiftZ" Then ;QidDi_s>  
            DeleteOperation eID,count IIP.yyh>  
            count=count-1 A[9NP-~  
        End If vXubY@k2  
        count=count+1 PPgW ^gj  
    Wend Yq0# #__  
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    'Set new shift in "A7<XN<  
    op.Type = "ShiftZ" `cO|RhD@  
    op.val1 = taq 6K//1U$  
    op.parent = parID YKq0f=Ij  
    AddOperation eID, op _?Ckq
 
    Print "Set aqueous humor thickness = " & taq-0.55 !w=,p.?V=  
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    '************************************************************************* hNVMz`r  
    'Radius and conic constant of anterior lens P C
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    '************************************************************************* VKf6|a
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 86{ZFtv  
    GetConic eID, entity, curv, conic sS'{QIRC'  
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    SetConic eID, entity, 1/Rant, CCant YE
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant x:C@)CAr  
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    '************************************************************************* 0x4l5x$8  
    'Radius and conic constant of posterior lens #W^_]Q=5R'  
    '************************************************************************* 2$DSBQEx  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) LT&/0  
    GetConic eID, entity, curv, conic HSql)iT  
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    SetConic eID, entity, 1/Rpost, CCpost ]gHLcr3  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost cE2Rr  
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    '************************************************************************* /'"R Mq  
    'Lens thickness (Position of posterior lens surface) CwB] )QV?  
    '************************************************************************* P|v ?
 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;3 dM@>5[  
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    ' Delete any z-shift(s) sOC| B  
    count = 0 I2W{tl  
    While GetOperationCount(eID)>count qAbd xd[  
        GetOperation eID, count, op c*jr5 Y  
        If op.Type="ShiftZ" Then {~"Em'}J  
            DeleteOperation eID,count Pd
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            count=count-1 (Y>U6  
        End If 0*{@E%9  
        count=count+1 X)y*#U  
    Wend ]ci RiMkT(  
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    'Set new z-shift ~"\P~cg0J  
    op.Type = "ShiftZ" y "<JE<X  
    op.val1 = tlens 2t.fD@  
    op.parent = parID 6XZN>#  
    AddOperation eID, op eNivlJ,K|@  
    Print "Set lens thickness = " & tlens 8@Q"YA3d+  
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    '************************************************************************* m9uUDq#GJ  
    'Lens index of refraction (s.o  
    '************************************************************************* z^"?sd  
    eID = FindMaterial( "Lens" ) @!Y.935/0  
    GetModelMaterial eID, mat z{AM2Z  
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    mat.Nd = nlens ^=3 ^HQ'Zm  
    SetModelMaterial eID, mat &,F elB0*  
    Print "Set lens index of refraction = " & nlens ~LSy7$rz  
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    '************************************************************************* p~ mN2x]  
    'Pupil diameter &(Go
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    '************************************************************************* BR%{bY^ 5p  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) '\4c "Ho  
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    'Adjust pupil diameter (trimming volume inner hole) xMLrLXy  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" N" 8*FiZ|  
'! #On/  
    ' Adjust pupil location to just in front of the lens e3G7K8  
    parID = FindFullName( "Geometry.Arizona Eye" ) V#+126  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .Ydr[  
    count = 0 F%9e@{  
    While GetOperationCount(eID)>count T,A!5V>cX  
        GetOperation eID, count, op Z^6A_:]j  
        If op.Type="ShiftZ" Then USH@:c#t  
            DeleteOperation eID,count !>?4[|?n<  
            count=count-1 ccIDMJ=2
 
        End If `4se7{'UK`  
        count=count+1 jo]m12ps  
    Wend Zjw
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    op.Type = "ShiftZ" PEK.Kt\M  
    op.val1 = taq-0.01 ':5Trx  
    op.parent = parID  >cC Gx  
    AddOperation eID, op ' }y]mFpF  
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    Print "Set pupil diameter = " & pupilDiam [P(rY  
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    'Update AZ Eye subassembly Description vsOdp:Yp9!  
    eID = FindFullName( "Geometry.Arizona Eye" ) \H},ouU  
    GetEntity eID, entity sDW"j\  
    entity.Description = "Accommodation = " & A & "D" z7
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    SetEntity eID, entity m T>b;  
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    Update [1t\|v  
    Print "DONE!" GGYX!=]~  
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End Sub =ip~J<sw&  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： GLbc/qs  
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Accommodation = 4 Diopters {o Q(<&Aw  
Pupil Diameter = 4 mm tg4LE?nv
 
Set aqueous humor thickness = 2.81 u&hDjE  
Set anterior lens radius = 10.4 and conic constant = -2.375869  m^W*[^p  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 !Qj)tS#Az  
Set lens thickness = 3.927 }[XB]Xf  
Set lens index of refraction = 1.42672 G~b`O20N  
Set pupil diameter = 4 :mCw.Jz<
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DONE! ::^qy^n